Network interface units (NIUs) are well known in the telephone industry as the interface between the telephone service provider and each subscriber. One example of such an NIU is shown in U.S. Pat. No. 4,979,209, having an enclosure installed at the subscriber location and serves as the demarcation point between the subscriber premise wiring and the telephone company distribution line. An NIU typically provides a subscriber section that is accessible to the subscriber and a service provider section that is restricted from access by the subscriber, but both sections are accessible to service representatives of the provider. The subscriber section provides a plurality of modules all connected to the main distribution cable for separate lines, usually for different subscribers, with the modules adapted for termination to ends of wires of the subscriber premise wiring.
Recently, NIUs have been devised that incorporate electronics necessary to receive fiber and coaxial signal connections, process the signals and establish a connection to subscriber premise wiring, a distinctly separate function from the telephony interconnection. Such electronics must receive appropriate electrical power to function, and is typically is either 60 VAC or 90 VAC Quasi-Square Wave. Certain coaxial distribution cables are of the type that integrally transmit appropriate levels of power, but provision must be made for alternate source of power to be utilized, such as a two-wire power conductor alongside the coaxial service drop.
In U.S. patent application Ser. No. 09/016,626 filed Jan. 30, 1998 and assigned to the assignee hereof, is disclosed a network interface module that is installable by accessing the subscriber section of the NIU, easily mechanically secured and electrically connected to the NIU in a single step, by latching into the enclosure, with the circuits to the main distribution cable being connected by an edge portion of a circuit card within the NIU being received into a connector of the module. Each module contains one connector for distribution circuit connection, at least one connector for subscriber wire connection, at least one test receptacle, and a ground bus connector also connectable to the circuit board of the NIU for grounding. Each subscriber wire connector includes a pivotable wire carrier that, upon insertion of ends of the tip and ring wires thereinto, is pivotable to urge the wire into an insulation displacement contact section for termination and electrical connection to circuits of the circuit board of the module. The module also is shown to include a gas protector for providing surge protection for the circuits of the module.
It is desired to provide a module that incorporates not only telephony connections to subscriber premise wiring but also test capability for electronics within the NIU associated with coaxial (CATV) connections to the subscriber, and additionally be programmable to provide power input to the electronics.
It is desired to provide such a module that accommodates either of two different sources of power utilized by the electronics.